This invention relates to a strengthening component added to a housing shell for a sealed compressor.
Refrigerant compressors are typically provided in a sealed housing. In such sealed compressors, the refrigerant is typically allowed to flow over a motor for driving a compressor pump unit and to cool the motor. In such housings, it is typically necessary to provide a fluid tight seal. Typically, a cylindrical center shell extends between the two ends of the compressor housing, and end caps are welded to each end of the center shell. The motor is mounted adjacent one end, which for purposes of this application will be referred to as the lower end. A pump unit is mounted near the opposed end, which for purposes of this application will be referred to as the upper end. While the terms xe2x80x9cupperxe2x80x9d and xe2x80x9clowerxe2x80x9d typically imply a vertical orientation, it should be understood that this application would also cover housings wherein the compressor is mounted horizontally, or some combination of horizontal and vertical. Thus, the term xe2x80x9clower endxe2x80x9d for describing one of the end caps should be interpreted to simply require the end cap adjacent the motor.
One type of modem compressor which has proven quite successful is a scroll compressor. In a scroll compressor, a pair of scroll members each include a generally spiral wrap extending from a base. The two wraps interfit to define compression chambers. The motor drives one of the two scroll members to orbit relative to the other, and as the two orbit the compression chambers defined between the two decrease in volume, compressing an entrapped refrigerant.
The interior of a sealed compressor housing is sometimes subject to relatively high pressure. Thus, burst testing is performed on the housing shells. The lower end cap utilized in sealed compressors frequently has a generally u-shaped hump formed in it. The outer periphery of this hump served as an alignment or guiding surface for the lower end of the center shell. During burst testing, this u-shaped hump has proved to be a weak point in the end cap, and has sometimes been subject to deformation, and failure. Thus, it would be desirable to strengthen the u-shaped hump in the lower end cap.
In the disclosed embodiment of this invention, a separate weld reinforcement member is positioned within a generally u-shaped structure in a lower end cap of a sealed compressor. More preferably, the u-shape extends circumferentially around the entire periphery of the compressor, although, in one embodiment there are circumferentially spaced portions. The weld reinforcement in the preferred embodiment is a ring which also extends along the entire circumference. The ring preferably has a slanted interior facing surface which will meet with a corresponding surface on a central portion of the lower end cap. The weld ring is first tack welded, then welded to both radially inner and outer surfaces of the end cap. The weld reinforcement provides a surface to bear the forces from the internal pressures, and relieve the transition of these forces through the relatively weak u-shaped hump.
Preferably, the weld reinforcement member is welded to both legs of the u-shape, and is spaced away from the end of the u-shape.
The present invention thus provides a lower end cap which is better resistant to the internal pressures in a sealed compressor. These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.